The present invention relates to a cutting insert for chip forming machining comprising a body having a generally polygonal shape and at least one cutting edge created by the intersection between an upper face and a side surface of the insert. The upper face constitutes a rake face contacting the chip formed during machining. The rake face functions as a chip former and includes a plurality of ridges.
There have heretofore been proposed in the prior art inserts having chip formers that comprise a plurality of ridges spaced along the cutting edge. One of these prior inserts is provided with a chip former which includes recesses located adjacent each other in the rake face. These recesses are arranged along the cutting edge and intersect each other, whereby the lines of intersection define ridges which extend generally perpendicularly in relation to the cutting edge. The lengths of the ridges are not identical. That is, the ridges are arranged with progressively decreasing lengths, the decrease occurring in a direction from the middle of the cutting edge towards the corner of the insert, whereby the ridge adjacent the corner is shorter than the middle ridge. Chips cut by this insert exhibit a tendency to approach the workpiece during turning such that there is a risk that the chips will scratch and thus damage the workpiece.
It is an object of the present invention to provide a cutting insert which urges the chip away from the workpiece during a working operation to minimize the risk of damage to the workpiece.
It is another object of the present invention to provide such a cutting insert having a plurality of cutting edges.